/mandos/release

To get this branch, use:
bzr branch http://bzr.recompile.se/loggerhead/mandos/release

« back to all changes in this revision

Viewing changes to Makefile

  • Committer: Teddy Hogeborn
  • Date: 2019-07-27 10:11:45 UTC
  • mto: This revision was merged to the branch mainline in revision 384.
  • Revision ID: teddy@recompile.se-20190727101145-jnpbpf8220gldbcd
Add dracut(8) support

Add support for the dracut(8) system for generating initramfs image
files; dracut is an alternative to the "initramfs-tools" package.

* .bzrignore (dracut-module/password-agent): Ignore new binary file.
* dracut-module: New directory for the dracut module.
* INSTALL (Prerequisites/Libraries/Mandos Client): Add dracut as an
                                                   alternative to
                                                   initramfs-tools,
                                                   and also add GLib.
* Makefile (DRACUTMODULE, GLIB_CFLAGS, GLIB_LIBS): New.
  (CPROGS): Add "dracut-module/password-agent".
  (DOCS): Add "dracut-module/password-agent.8mandos".
  (dracut-module/password-agent.8mandos): New.
  (dracut-module/password-agent.8mandos.xhtml): - '' -
  (dracut-module/password-agent): - '' -
  (check): Add command to run tests of password-agent(8mandos).
  (install-client-nokey): Also install the dracut module directory,
                          its files, and the password-agent(8mandos)
                          manual page.
  (install-client): To update the initramfs image file, run
                    update-initramfs or dracut depending on what is
                    installed.
  (uninstall-client): - '' - and also uninstall the the files in the
                      dracut module directory, that directory itself,
                      and the password-agent(8mandos) manual page.
* debian/control (Build-Depends): Add "libglib2.0-dev (>=2.40)".
  (Package: mandos-client/Depends): Add "dracut (>= 044+241-3)" as an
                                    alternative dependency to
                                    initramfs-tools.
  (Package: mandos-client/Conflicts): New; set to
                                      "dracut-config-generic".
  (debian/mandos-client.README.Debian): Document alternative commands
                                        to update the initramfs image
                                        for when dracut is used.
* debian/mandos-client.postinst (update_initramfs): Use alternative
                                                    commands to update
                                                    the initramfs
                                                    image for when
                                                    dracut is used.
* debian/tests/control (password-agent, password-agent-suid): Add two
                                                              new tests.
* dracut-module/ask-password-mandos.path: New.
* dracut-module/ask-password-mandos.service: - '' -
* dracut-module/cmdline-mandos.sh: - '' -
* dracut-module/module-setup.sh: - '' -
* dracut-module/password-agent.c: - '' -
* dracut-module/password-agent.xml: - '' -
* initramfs-unpack: Use the dracut "skipcpio" command, if available.
                    Also be more flexible and try hard to detect where
                    compressed data starts.
* plugins.d/mandos-client.xml (SECURITY): Be more precise that the
                                          mandos-client binary might
                                          not always be setuid, but
                                          that the program assumes
                                          that it has been started
                                          that way.
* plugins.d/password-prompt.c: Add new "--prompt" option.
  (conflict_detection): First try to detect the new PID file of
                        plymouth.
  (main): Define and use new "prompt" variable.
* plugins.d/password-prompt.xml (SYNOPSIS): Show new --prompt option.
  (DESCRIPTION): Describe new behavior of looking for plymouth PID
                 file.
  (OPTIONS): Document new "--prompt" option.
  (ENVIRONMENT): Clarify that the CRYPTTAB_SOURCE and CRYPTTAB_NAME
                 environment variables are not used if the --prompt
                 option is used.  Remove unnecessarily specific
                 details about where the CRYPTTAB_SOURCE and
                 CRYPTTAB_NAME comes from, since this can now be
                 either initramfs-tools or dracut.
  (SEE ALSO): Remove superfluous crypttab(5) reference, and add commas
              to separate the other references.
* plugins.d/plymouth.c: Add new "--prompt" and "--debug" options.
  (debug): New global flag.
  (fprintf_plus): New function, used for debug output.
  (exec_and_wait): Add extra "const" to "argv" argument.
  (main): Define and use new "prompt" variable.  Add debug output.
  (main/options, main/parse_opt): New; used to parse options.
* plugins.d/plymouth.xml (SYNOPSIS): Show new options.
  (OPTIONS): Document new options.
  (ENVIRONMENT): Clarify that the cryptsource and crypttarget
                 environment variables are not used if the --prompt
                 option is used.  Remove unnecessarily specific
                 details about where the cryptsource and crypttarget
                 comes from, since this can now be either
                 initramfs-tools or dracut.
  (EXAMPLE): Add an example using an option.
  (SEE ALSO): Remove superfluous crypttab(5) reference.
* plugins.d/splashy.xml (ENVIRONMENT): Clarify that the cryptsource
                                       and crypttarget environment
                                       variables are not used if the
                                       --prompt option is used.
                                       Remove unnecessarily specific
                                       details about where the
                                       cryptsource and crypttarget
                                       comes from, since this can now
                                       be either initramfs-tools or
                                       dracut.
  (SEE ALSO): Remove superfluous crypttab(5) reference.
* plugins.d/usplash.xml (ENVIRONMENT): Clarify that the cryptsource
                                       and crypttarget environment
                                       variables are not used if the
                                       --prompt option is used.
                                       Remove unnecessarily specific
                                       details about where the
                                       cryptsource and crypttarget
                                       comes from, since this can now
                                       be either initramfs-tools or
                                       dracut.
  (SEE ALSO): Remove superfluous crypttab(5) reference.

Show diffs side-by-side

added added

removed removed

Lines of Context:
Makefile
29
29
 
30
30
# For info about _FORTIFY_SOURCE, see feature_test_macros(7)
31
31
# and <https://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html>.
32
 
FORTIFY:=-fstack-protector-all -fPIC
33
 
CPPFLAGS+=-D_FORTIFY_SOURCE=3
 
32
FORTIFY:=-D_FORTIFY_SOURCE=2 -fstack-protector-all -fPIC
34
33
LINK_FORTIFY_LD:=-z relro -z now
35
34
LINK_FORTIFY:=
36
35
 
42
41
#COVERAGE=--coverage
43
42
OPTIMIZE:=-Os -fno-strict-aliasing
44
43
LANGUAGE:=-std=gnu11
45
 
CPPFLAGS+=-D_FILE_OFFSET_BITS=64
46
44
htmldir:=man
47
 
version:=1.8.16
 
45
version:=1.8.4
48
46
SED:=sed
49
 
PKG_CONFIG?=pkg-config
50
47
 
51
48
USER:=$(firstword $(subst :, ,$(shell getent passwd _mandos \
52
49
        || getent passwd nobody || echo 65534)))
53
50
GROUP:=$(firstword $(subst :, ,$(shell getent group _mandos \
54
51
        || getent group nogroup || echo 65534)))
55
52
 
56
 
LINUXVERSION:=$(shell uname --kernel-release)
57
 
 
58
53
## Use these settings for a traditional /usr/local install
59
54
# PREFIX:=$(DESTDIR)/usr/local
60
55
# CONFDIR:=$(DESTDIR)/etc/mandos
76
71
STATEDIR:=$(DESTDIR)/var/lib/mandos
77
72
LIBDIR:=$(shell \
78
73
        for d in \
79
 
        "/usr/lib/`dpkg-architecture \
80
 
                        -qDEB_HOST_MULTIARCH 2>/dev/null`" \
 
74
        "/usr/lib/`dpkg-architecture -qDEB_HOST_MULTIARCH 2>/dev/null`" \
81
75
        "`rpm --eval='%{_libdir}' 2>/dev/null`" /usr/lib; do \
82
76
                if [ -d "$$d" -a "$$d" = "$${d%/}" ]; then \
83
77
                        echo "$(DESTDIR)$$d"; \
86
80
        done)
87
81
##
88
82
 
89
 
SYSTEMD:=$(DESTDIR)$(shell $(PKG_CONFIG) systemd \
90
 
                        --variable=systemdsystemunitdir)
91
 
TMPFILES:=$(DESTDIR)$(shell $(PKG_CONFIG) systemd \
92
 
                        --variable=tmpfilesdir)
93
 
SYSUSERS:=$(DESTDIR)$(shell $(PKG_CONFIG) systemd \
94
 
                        --variable=sysusersdir)
 
83
SYSTEMD:=$(DESTDIR)$(shell pkg-config systemd --variable=systemdsystemunitdir)
 
84
TMPFILES:=$(DESTDIR)$(shell pkg-config systemd --variable=tmpfilesdir)
95
85
 
96
 
GNUTLS_CFLAGS:=$(shell $(PKG_CONFIG) --cflags-only-I gnutls)
97
 
GNUTLS_LIBS:=$(shell $(PKG_CONFIG) --libs gnutls)
98
 
AVAHI_CFLAGS:=$(shell $(PKG_CONFIG) --cflags-only-I avahi-core)
99
 
AVAHI_LIBS:=$(shell $(PKG_CONFIG) --libs avahi-core)
100
 
GPGME_CFLAGS:=$(shell $(PKG_CONFIG) --cflags-only-I gpgme 2>/dev/null \
101
 
        || gpgme-config --cflags; getconf LFS_CFLAGS)
102
 
GPGME_LIBS:=$(shell $(PKG_CONFIG) --libs gpgme 2>/dev/null \
103
 
        || gpgme-config --libs; getconf LFS_LIBS; \
 
86
GNUTLS_CFLAGS:=$(shell pkg-config --cflags-only-I gnutls)
 
87
GNUTLS_LIBS:=$(shell pkg-config --libs gnutls)
 
88
AVAHI_CFLAGS:=$(shell pkg-config --cflags-only-I avahi-core)
 
89
AVAHI_LIBS:=$(shell pkg-config --libs avahi-core)
 
90
GPGME_CFLAGS:=$(shell gpgme-config --cflags; getconf LFS_CFLAGS)
 
91
GPGME_LIBS:=$(shell gpgme-config --libs; getconf LFS_LIBS; \
104
92
        getconf LFS_LDFLAGS)
105
 
LIBNL3_CFLAGS:=$(shell $(PKG_CONFIG) --cflags-only-I libnl-route-3.0)
106
 
LIBNL3_LIBS:=$(shell $(PKG_CONFIG) --libs libnl-route-3.0)
107
 
GLIB_CFLAGS:=$(shell $(PKG_CONFIG) --cflags glib-2.0)
108
 
GLIB_LIBS:=$(shell $(PKG_CONFIG) --libs glib-2.0)
 
93
LIBNL3_CFLAGS:=$(shell pkg-config --cflags-only-I libnl-route-3.0)
 
94
LIBNL3_LIBS:=$(shell pkg-config --libs libnl-route-3.0)
 
95
GLIB_CFLAGS:=$(shell pkg-config --cflags glib-2.0)
 
96
GLIB_LIBS:=$(shell pkg-config --libs glib-2.0)
109
97
 
110
98
# Do not change these two
111
 
CFLAGS+=$(WARN) $(DEBUG) $(FORTIFY) $(COVERAGE) $(OPTIMIZE) \
112
 
        $(LANGUAGE) -DVERSION='"$(version)"'
 
99
CFLAGS+=$(WARN) $(DEBUG) $(FORTIFY) $(COVERAGE) \
 
100
        $(OPTIMIZE) $(LANGUAGE) -DVERSION='"$(version)"'
113
101
LDFLAGS+=-Xlinker --as-needed $(COVERAGE) $(LINK_FORTIFY) $(strip \
114
102
        ) $(foreach flag,$(LINK_FORTIFY_LD),-Xlinker $(flag))
115
103
 
159
147
 
160
148
objects:=$(addsuffix .o,$(CPROGS))
161
149
 
162
 
.PHONY: all
163
150
all: $(PROGS) mandos.lsm
164
151
 
165
 
.PHONY: doc
166
152
doc: $(DOCS)
167
153
 
168
 
.PHONY: html
169
154
html: $(htmldocs)
170
155
 
171
156
%.5: %.xml common.ent legalnotice.xml
288
273
                $@)
289
274
 
290
275
# Need to add the GnuTLS, Avahi and GPGME libraries
291
 
plugins.d/mandos-client: CFLAGS += $(GNUTLS_CFLAGS) $(strip \
292
 
        ) $(AVAHI_CFLAGS) $(GPGME_CFLAGS)
293
 
plugins.d/mandos-client: LDLIBS += $(GNUTLS_LIBS) $(strip \
294
 
        ) $(AVAHI_LIBS) $(GPGME_LIBS)
 
276
plugins.d/mandos-client: plugins.d/mandos-client.c
 
277
        $(LINK.c) $^ $(GNUTLS_CFLAGS) $(AVAHI_CFLAGS) $(strip\
 
278
                ) $(GPGME_CFLAGS) $(GNUTLS_LIBS) $(strip\
 
279
                ) $(AVAHI_LIBS) $(GPGME_LIBS) $(LOADLIBES) $(strip\
 
280
                ) $(LDLIBS) -o $@
295
281
 
296
282
# Need to add the libnl-route library
297
 
plugin-helpers/mandos-client-iprouteadddel: CFLAGS += $(LIBNL3_CFLAGS)
298
 
plugin-helpers/mandos-client-iprouteadddel: LDLIBS += $(LIBNL3_LIBS)
 
283
plugin-helpers/mandos-client-iprouteadddel: plugin-helpers/mandos-client-iprouteadddel.c
 
284
        $(LINK.c) $(LIBNL3_CFLAGS) $^ $(LIBNL3_LIBS) $(strip\
 
285
                ) $(LOADLIBES) $(LDLIBS) -o $@
299
286
 
300
287
# Need to add the GLib and pthread libraries
301
 
dracut-module/password-agent: CFLAGS += $(GLIB_CFLAGS)
302
 
# Note: -lpthread is unnecessary with the GNU C library 2.34 or later
303
 
dracut-module/password-agent: LDLIBS += $(GLIB_LIBS) -lpthread
304
 
 
305
 
.PHONY: clean
 
288
dracut-module/password-agent: dracut-module/password-agent.c
 
289
        $(LINK.c) $(GLIB_CFLAGS) $^ $(GLIB_LIBS) -lpthread $(strip\
 
290
                ) $(LOADLIBES) $(LDLIBS) -o $@
 
291
 
 
292
.PHONY : all doc html clean distclean mostlyclean maintainer-clean \
 
293
        check run-client run-server install install-html \
 
294
        install-server install-client-nokey install-client uninstall \
 
295
        uninstall-server uninstall-client purge purge-server \
 
296
        purge-client
 
297
 
306
298
clean:
307
299
        -rm --force $(CPROGS) $(objects) $(htmldocs) $(DOCS) core
308
300
 
309
 
.PHONY: distclean
310
301
distclean: clean
311
 
.PHONY: mostlyclean
312
302
mostlyclean: clean
313
 
.PHONY: maintainer-clean
314
303
maintainer-clean: clean
315
304
        -rm --force --recursive keydir confdir statedir
316
305
 
317
 
.PHONY: check
318
306
check: all
319
307
        ./mandos --check
320
308
        ./mandos-ctl --check
324
312
        ./dracut-module/password-agent --test
325
313
 
326
314
# Run the client with a local config and key
327
 
.PHONY: run-client
328
 
run-client: all keydir/seckey.txt keydir/pubkey.txt \
329
 
                        keydir/tls-privkey.pem keydir/tls-pubkey.pem
330
 
        @echo '######################################################'
331
 
        @echo '# The following error messages are harmless and can  #'
332
 
        @echo '#  be safely ignored:                                #'
333
 
        @echo '## From plugin-runner:                               #'
334
 
        @echo '# setgid: Operation not permitted                    #'
335
 
        @echo '# setuid: Operation not permitted                    #'
336
 
        @echo '## From askpass-fifo:                                #'
337
 
        @echo '# mkfifo: Permission denied                          #'
338
 
        @echo '## From mandos-client:                               #'
339
 
        @echo '# Failed to raise privileges: Operation not permi... #'
340
 
        @echo '# Warning: network hook "*" exited with status *     #'
341
 
        @echo '# ioctl SIOCSIFFLAGS +IFF_UP: Operation not permi... #'
342
 
        @echo '# Failed to bring up interface "*": Operation not... #'
343
 
        @echo '#                                                    #'
344
 
        @echo '# (The messages are caused by not running as root,   #'
345
 
        @echo '# but you should NOT run "make run-client" as root   #'
346
 
        @echo '# unless you also unpacked and compiled Mandos as    #'
347
 
        @echo '# root, which is also NOT recommended.)              #'
348
 
        @echo '######################################################'
 
315
run-client: all keydir/seckey.txt keydir/pubkey.txt keydir/tls-privkey.pem keydir/tls-pubkey.pem
 
316
        @echo "###################################################################"
 
317
        @echo "# The following error messages are harmless and can be safely     #"
 
318
        @echo "# ignored:                                                        #"
 
319
        @echo "# From plugin-runner: setgid: Operation not permitted             #"
 
320
        @echo "#                     setuid: Operation not permitted             #"
 
321
        @echo "# From askpass-fifo:  mkfifo: Permission denied                   #"
 
322
        @echo "# From mandos-client:                                             #"
 
323
        @echo "#             Failed to raise privileges: Operation not permitted #"
 
324
        @echo "#             Warning: network hook \"*\" exited with status *      #"
 
325
        @echo "#                                                                 #"
 
326
        @echo "# (The messages are caused by not running as root, but you should #"
 
327
        @echo "# NOT run \"make run-client\" as root unless you also unpacked and  #"
 
328
        @echo "# compiled Mandos as root, which is also NOT recommended.)        #"
 
329
        @echo "###################################################################"
349
330
# We set GNOME_KEYRING_CONTROL to block pam_gnome_keyring
350
331
        ./plugin-runner --plugin-dir=plugins.d \
351
332
                --plugin-helper-dir=plugin-helpers \
358
339
keydir/seckey.txt keydir/pubkey.txt keydir/tls-privkey.pem keydir/tls-pubkey.pem: mandos-keygen
359
340
        install --directory keydir
360
341
        ./mandos-keygen --dir keydir --force
361
 
        if ! [ -e keydir/tls-privkey.pem ]; then \
362
 
                install --mode=u=rw /dev/null keydir/tls-privkey.pem; \
363
 
        fi
364
 
        if ! [ -e keydir/tls-pubkey.pem ]; then \
365
 
                install --mode=u=rw /dev/null keydir/tls-pubkey.pem; \
366
 
        fi
367
342
 
368
343
# Run the server with a local config
369
 
.PHONY: run-server
370
344
run-server: confdir/mandos.conf confdir/clients.conf statedir
371
345
        ./mandos --debug --no-dbus --configdir=confdir \
372
346
                --statedir=statedir $(SERVERARGS)
383
357
statedir:
384
358
        install --directory statedir
385
359
 
386
 
.PHONY: install
387
360
install: install-server install-client-nokey
388
361
 
389
 
.PHONY: install-html
390
362
install-html: html
391
363
        install --directory $(htmldir)
392
364
        install --mode=u=rw,go=r --target-directory=$(htmldir) \
393
365
                $(htmldocs)
394
366
 
395
 
.PHONY: install-server
396
367
install-server: doc
397
368
        install --directory $(CONFDIR)
398
369
        if install --directory --mode=u=rwx --owner=$(USER) \
401
372
        elif install --directory --mode=u=rwx $(STATEDIR); then \
402
373
                chown -- $(USER):$(GROUP) $(STATEDIR) || :; \
403
374
        fi
404
 
        if [ "$(TMPFILES)" != "$(DESTDIR)" \
405
 
                        -a -d "$(TMPFILES)" ]; then \
 
375
        if [ "$(TMPFILES)" != "$(DESTDIR)" -a -d "$(TMPFILES)" ]; then \
406
376
                install --mode=u=rw,go=r tmpfiles.d-mandos.conf \
407
377
                        $(TMPFILES)/mandos.conf; \
408
378
        fi
409
 
        if [ "$(SYSUSERS)" != "$(DESTDIR)" \
410
 
                        -a -d "$(SYSUSERS)" ]; then \
411
 
                install --mode=u=rw,go=r sysusers.d-mandos.conf \
412
 
                        $(SYSUSERS)/mandos.conf; \
413
 
        fi
414
379
        install --mode=u=rwx,go=rx mandos $(PREFIX)/sbin/mandos
415
380
        install --mode=u=rwx,go=rx --target-directory=$(PREFIX)/sbin \
416
381
                mandos-ctl
445
410
        gzip --best --to-stdout intro.8mandos \
446
411
                > $(MANDIR)/man8/intro.8mandos.gz
447
412
 
448
 
.PHONY: install-client-nokey
449
413
install-client-nokey: all doc
450
414
        install --directory $(LIBDIR)/mandos $(CONFDIR)
451
415
        install --directory --mode=u=rwx $(KEYDIR) \
452
416
                $(LIBDIR)/mandos/plugins.d \
453
417
                $(LIBDIR)/mandos/plugin-helpers
454
 
        if [ "$(SYSUSERS)" != "$(DESTDIR)" \
455
 
                        -a -d "$(SYSUSERS)" ]; then \
456
 
                install --mode=u=rw,go=r sysusers.d-mandos.conf \
457
 
                        $(SYSUSERS)/mandos-client.conf; \
458
 
        fi
459
418
        if [ "$(CONFDIR)" != "$(LIBDIR)/mandos" ]; then \
460
419
                install --mode=u=rwx \
461
420
                        --directory "$(CONFDIR)/plugins.d" \
466
425
        install --mode=u=rwx,go=rx \
467
426
                --target-directory=$(LIBDIR)/mandos plugin-runner
468
427
        install --mode=u=rwx,go=rx \
469
 
                --target-directory=$(LIBDIR)/mandos \
470
 
                mandos-to-cryptroot-unlock
 
428
                --target-directory=$(LIBDIR)/mandos mandos-to-cryptroot-unlock
471
429
        install --mode=u=rwx,go=rx --target-directory=$(PREFIX)/sbin \
472
430
                mandos-keygen
473
431
        install --mode=u=rwx,go=rx \
530
488
        gzip --best --to-stdout dracut-module/password-agent.8mandos \
531
489
                > $(MANDIR)/man8/password-agent.8mandos.gz
532
490
 
533
 
.PHONY: install-client
534
491
install-client: install-client-nokey
535
492
# Post-installation stuff
536
493
        -$(PREFIX)/sbin/mandos-keygen --dir "$(KEYDIR)"
537
494
        if command -v update-initramfs >/dev/null; then \
538
495
            update-initramfs -k all -u; \
539
496
        elif command -v dracut >/dev/null; then \
540
 
            for initrd in $(DESTDIR)/boot/initr*-$(LINUXVERSION); do \
 
497
            for initrd in $(DESTDIR)/boot/initr*-$(shell uname --kernel-release); do \
541
498
                if [ -w "$$initrd" ]; then \
542
499
                    chmod go-r "$$initrd"; \
543
500
                    dracut --force "$$initrd"; \
546
503
        fi
547
504
        echo "Now run mandos-keygen --password --dir $(KEYDIR)"
548
505
 
549
 
.PHONY: uninstall
550
506
uninstall: uninstall-server uninstall-client
551
507
 
552
 
.PHONY: uninstall-server
553
508
uninstall-server:
554
509
        -rm --force $(PREFIX)/sbin/mandos \
555
510
                $(PREFIX)/sbin/mandos-ctl \
562
517
        update-rc.d -f mandos remove
563
518
        -rmdir $(CONFDIR)
564
519
 
565
 
.PHONY: uninstall-client
566
520
uninstall-client:
567
521
# Refuse to uninstall client if /etc/crypttab is explicitly configured
568
522
# to use it.
599
553
        if command -v update-initramfs >/dev/null; then \
600
554
            update-initramfs -k all -u; \
601
555
        elif command -v dracut >/dev/null; then \
602
 
            for initrd in $(DESTDIR)/boot/initr*-$(LINUXVERSION); do \
 
556
            for initrd in $(DESTDIR)/boot/initr*-$(shell uname --kernel-release); do \
603
557
                test -w "$$initrd" && dracut --force "$$initrd"; \
604
558
            done; \
605
559
        fi
606
560
 
607
 
.PHONY: purge
608
561
purge: purge-server purge-client
609
562
 
610
 
.PHONY: purge-server
611
563
purge-server: uninstall-server
612
564
        -rm --force $(CONFDIR)/mandos.conf $(CONFDIR)/clients.conf \
613
565
                $(DESTDIR)/etc/dbus-1/system.d/mandos.conf
618
570
                $(DESTDIR)/var/run/mandos.pid
619
571
        -rmdir $(CONFDIR)
620
572
 
621
 
.PHONY: purge-client
622
573
purge-client: uninstall-client
623
574
        -shred --remove $(KEYDIR)/seckey.txt $(KEYDIR)/tls-privkey.pem
624
575
        -rm --force $(CONFDIR)/plugin-runner.conf \